Dental articulator



May 19, 1942- D. NEUSTADT DENTAL ARTICULATOR Filed Jan. 18, 1941 2 Sheets-Sheet 1 7' INVENTOR.

ATTORNEYS May 19, 1942. D. NEUSTADT DENTAL ARTIGULATOR Filed Jan. 18, 1941 2 Sheets-Sheet 2 ATTORNEYS Patented May 19, 1942 DENTAL ARTICULATOR David Neustadt, New York, N. Y., assignor to Columbia Dentoform Corp., New a corporation of New York York, N. Y.,

Application January 18, 1941, Serial No. 374,955

'3 Claims.

My invention relates to a new and useful dental articulator.

One of the objects of the invention is to provide an improved articulator for use in making partial dentures.

Another object of the invention is to provide an articulator which will have the same movements as the condyles of the lower jaw, including the up-and-down' movement, the lateral movement, and the protrusive movement.

Another object of the invention is to provide an articulator for use in making a partial denture, in which the artificial teeth which are supplied to replace the missing teeth, will have the desired functional articulation.

Another object of the invention is to'provide an articulator which has improved means for detachably holding the models of the proposed dentures.

Another and very important object of the invention is to provide an articulator in which the members of the articulator have the same relative movements as the jaws, said members being guided in said movements by the models of the proposed dentures.

Other objects of the invention will be set forth in the following description and drawings which illustrate preferred embodiments thereof.

Fig. 1 is a top plan view of the improved device, made according to the first embodiment.

Fig. 2 is a side elevation, a portion of the representation of the upper member having been broken away, in order to show the interior construction thereof.

' Fig. 3 is a rear end elevation, taken at the right-hand end of Fig. 1. In this view, the joint is adjusted to permit only the up-and-down movement of the lower member relative to the upper member.

Fig. 4 is a detail View of the joint of the device, when this joint is adjusted for the lateral and protrusive movements, as well as the upand-down movement.

Fig. 5 is an elevation on the line 55 of Fig. 3.

Fig. 6 is an elevation, partially in section, on the line 6-6 of Fig. 2.

Fig. 6A is an end view of the ball-shaped socket member of the lower member of the device.

Fig. 7 is an elevation of a modified joint.

Fig. 8 is a sectional view on the line 8'8 of Fig. '7.

Fig. 9 is a sectional view on the line 9-9 of Fig. 8.

In making a denture, especially a partial denture in which the mouth has some of its natural teeth, it is necessary to make allowance for the lateral and protrusive movements of the lower jaw of the patient, relative to the upper jaw. If this is not done, the denture is unsatisfactory, because the natural teeth grind into the denture. This seriously weakens the natural teeth.

Due to the extra difiiculty and expense, the

models of the upper and lower jaw of the patient, including the models of natural teeth and of the proposed denture or dentures, have often been tested only in an articulator Whose joint permitted only an up-and-down movement. If the models were tested in an articulator whose joint simulated the lateral movement of the patients lower jaw, said joint was made by special and expensive methods to follow the lateral movements of the patients jaw, but these lateral movements were determined by the construction of the joint, and not by the models themselves.

Likewise, it was necessary to ship the articulator, with the models therein, from the dental laboratory, to the dentist.

According to my invention, the movements of the jaw members of the articulator are guided whollyby the models which are held in said jaw members. The models are readily detachable from the members of the articulator, and said articulator can be made in a standard size or sizes, so that it is not necessary to ship the models while they are assembled with the articulator.

The articulator comprises an upper member I, and a lower member 2. The upper member I has a cup-shaped casing portion 3, which is provided in its top wall with a series of openings 4. The model 5 of the upper jaw has its upper portion fitting snugly but removably in this cup shaped casing portion 3. This model 5 is provided with bosses 6, which fit removably in the bores 01' openings 4. These bosses 6 thus prevent any shifting of the model 5 relative to the cup-shaped casing 3. This model is made of any suitable material, which may be plaster of Paris or other moldable material, or said model may be a replica of the original plaster of Paris model orthe like. This replica can be made of any heat-resistant investing material.

As shown in Fig. 2, the model 5 is provided at its front with a locking recess, in which the and removably. in position.

At its rear end, the upper member I is provided with integral depending lugs I0. These lugs are provided with bores in which the pivot pin II is turnably mounted. This pivot pin II has an enlarged boss I2 at one end thereof. The collar I4 is removably connected by a set screw or the like, to the respective end of the pivot pin I I, so that the pivot pin I I cannot shift laterally relative to lugs I0. This pivot pin IIis provided with a knurled operating head I 5.

Intermediate the lugs II), the pivot pin I I is.

provided with a ball-member I3, which has an integral radial pin IT. This member I6 may be of partial spherical shape. In the specific embodiment shown, its shape corresponds to a sphere whose ends have been cut off along two spaced planes which are perpendicular to the axis of the pin I I.

The lower member 2 is provided with a cupshaped casing portion I8 which is similar to the cup-shaped portion 3. The model I9 of the lower jaw restoration, is heldremovably in this cupshaped member I8. The bottom wall of the cupshaped member I8 is provided with openings which are similar to the openings 4, and the bottom model I9 has bosses which are similar to the bosses 6. The lower casing I8 may also have a locking pin, like the pin I.

, The rear end of the lower member 2 is provided with an upstanding post 20. This post 20 is provided with a forwardly-projecting, longitudinal arm 2|. A vertical stop screw 22 is held adjustably in a corresponding tapped bore of the longitudinal arm 2|, and this screw 22 can be held in its adjusted position, by a lock nut 23. The arm 28 is provided with a socket of partial spherical shape, in which a recessed socket ball 24 is turnable in all directions. As shown in Fig. 4, this recessed ball 24 is provided with a radial recess As shown in Fig. 6A, the walls of this radial recess 25 are provided with concave grooves 25a, so that the ball-member I6 can be radially inserted into this radial recess 25. 'The walls of this recess are planar, save for the concave grooves 25a. The ball-member I6 fits into and between these grooves 25a. Hence the ball-member I6 cannot move laterally in said recess, but said ball-member I6 can move forwards and backwards in said recess 25, relative to the inner Wall of said recess 25. The pin I I. fits fairly closely between the planar walls of said recess so that the pin I I can move forwards and backwards in unison with ball-member I6 and said pin II can turn around its own axis, but it cannot tilt perpendicular to its axis.

The post 20 is provided with an inclined tapped bore, in which the shank of the clamping screw 21 is mounted. After the ball I6 has been radially inserted into the recess 25, the pin .II can be turned in unison with the ball-member I6 until the pin II of the ball-member I6 is in the position illustrated in Figs. 2 and 5. The screw 21 can then be tightened, so as to clamp the ball 24 in its socket.

The member I can then be freely raised and lowered, and the top of the adjustable screw 22 acts as a stop.

When the pin I! is in the position shown in Figs. 2 and 5, the jaw members can only turn around a horizontal axis, thus providing for the relative up-and-down movement of the lower jaw relative to the upper jaw, but without any lateral or protrusive movements. This is designated as the centric movement of the model. Since the socket 24 is rigidly clamped in position, and since pin II fits snugly in the bores of lugs ID, the jaw members I and 2 cannot move longitudinally relative to each other. In such position the free end of pin II substantially abuts the wall of the recess in post 20, so that pin I I cannot move longitudinally relative to ball 24.

In order to provide the lateral and protrusive movements, the set screw 21 is loosened and the pin II is turned in unison with the member 24, until the pin I1 is in the outward position shown in Fig. 4. The screw 21 is then tightened only slightly, so as to prevent the bal1 24 from falling out of position. However, the ball 24 can turn freely in alldirections relative to post 20, in a universal turning movement. In this position, the pin II can also move outwardly relative to the member 24, and said pin II can also turn freely'about a vertical axis, in unison with the socket 24. The top of the screw 21 has a con cave shape, in order to conform to the ball-shape of the member 24, and to permit the member 24 to turn freely relative to post 20 and screw 21.

In the second embodiment of Figs.- 7-9, the pivot pin II is replaced by a pivot pin I Ia, which has a ball 28-fixed thereto. This ball 28 fits partially into a corresponding partial spherical recess which is'provided in the integral extension 20a of the post 20.

A pair of tension springs 24 are provided. Each tension spring has one end thereof'connected to the post 20, and the other end thereof is connected to the respective end of the pivotpin Ila. These tension springs therefore maintain the ball 28 in yielding contact with its socket.

The jaw members can therefore be moved rela tive to each other about the horizontal axis and they can also be given the desired lateral and protrusive movements.

During the lateral and-protrusive movements of the jaw members, the models 5 and I9 remain in free sliding contact throughout. The joint itself does not fix or determine these lateral and protrusive movements. Hence the laboratory technician or the dentist can study and perfect the models, under the same conditions as though they were dentures which had been installed in the mouth of the patient.

It is very simple to remove the models 5 and I9 and send them from the dental laboratory to the dentist, and the model of any denture will fit in any articulator, which is a great convenience.

The ball-member I6 is rigidly fixed to the pivot pin I I in any suitable manner. The longitudinal axes of the grooves 25a are parallel to each other and perpendicular to the axes of the pin I I. The concave walls of these grooves 25 are equi-distant from the center of the ball-member 46. Save for the concave walls of the grooves 25a, the radial walls of the recess 25 are planar and parallel to each other, and the longitudinal axes of said planar walls are perpendicular to the axis 0 the pin I I.

' For convenience, the device will be described and claimed with respect to the position illustrated in Fig. 2, in which the jaw members can move up and down, relative to each other, around a horizontal axis.

In the embodiments disclosed, the socket recess is provided in the lower jaw member, but it would not be departing from the invention if the parts of the joint were reversed in location or in function and such reversal is included in the claims- If desired, the screw 21 can be loosened while the parts of the joint are in the relative position shown in Fig. 2, so as to retain the member 24 movably in position. The jaw members can be moved relative to each other in substantial lateral and protrusive movements, without turning the member 24 to the position shown in Fig. 4. In each embodiment, one of the jaw members has a socket recess and the joint includes a ballmember which is located in said socket recess and which has a universal movement relative to the wall of said socket recess. This ball-member is the member 24 in the first embodiment, and it is the member 28 in the second embodiment. In both embodiments, the construction of the joint permits the upper jaw-member to move longitudinally and also laterally relative to the wall of said recess, while the parts of the joint are func-,

tionally assembled, so that the jaw members can move up and down relative to each other.

I have shown preferred embodiments of my invention, but it is clear that numerous changes and omissions can be made without departing from its spirit.

For example, instead of forming through-andthrough perforations 4 in the end-wall of the respective cup-shaped recess, said end-wall maybe recessed to receive the projection or projections 6. The use of a plurality of projections 6 is preferred, in order to prevent the model from turning relative to its recess, but a single projection 6 is within the scope of the invention.

'I claim:

1. A dental articulator comprising a lower-jaw member which has an upstanding projection, an upper-jaw member having depending means, said projection having a first cup-shaped recess, a

first ball-member located in said recess and turnable in said first cup-shaped recess about a vertical axis and also about a horizontal axis, said upstanding projection having latch-means adapted to retain said first ball-member in said first cup-shaped recess, said first ball-member having a radial slot which has opposed walls and which is open at its outer end, a pivot-member connected to said depending means, said opposed walls having aligned radial supplemental recesses, said pivot-member having a supplemental ball-member which is located partially in said supplemental recesses, said pivot-member being located between said opposed walls, said upperjaw member and said pivot-member and said supplemental ball-member being movable in unison longitudinally back-and-forth relative to said first ball-member, said supplemental ball-.

member being movable relative to the first ballmember around a horizontal axis and a vertical axis, the walls of said supplemental recesses holding said supplemental ball-member against substantial movement relative to the first ball-member in a direction parallel to the axis of said pivot-member.

2. A dental articulator comprising a lower-jaw member which has an upstanding projection, an

upper-jaw member having depending means, said projection having'a first cup-shaped recess, a first ball-member located in said recess and turnable in said first cup-shaped recess about a vertical axis and also about a horizontal axis, said upstanding projection having latch-means adapted to retain saidfirst ball-member in said first cup-shaped recess, said first ball-member having a radial slot which has opposed walls and which is open at its outer end, a pivot-member connected to said depending means, said opposed walls having aligned radial supplemental recesses, said pivot-member having a supplemental ball-member which is located partially in said supplemental recesses, said pivot-member being located between said opposed walls, said upperjaw member and said pivot-member and said supplemental ball-member being movable in unison longitudinally back-and-forth relative to said first ball-member, said supplemental ballmember being movable relative to the first ballmember around a horizontal axis and a vertical axis, the walls of said supplemental recesses holding said supplemental ball-member against substantial movement relative to the first ball-member in a direction parallel to the axis of said pivot-member, said. supplemental ball-member having a radial pin. I

3. A dental articulator comprising a lower-jaw member which has an upstanding projection, an.

upper-jaw member having depending means, said projection having a first cup-shaped recess, a first ball-member located in said recess and turnable V in said first cup-shaped recess about a vertical axis and also about a horizontal axis, said upstanding projection having latch-means adapted to retain said first ball-member in said first cupshaped recess, said first ball-member having a radial slot which has opposed walls and which is open at its outer end, a pivot-member connected ber being movable relative to the first ball-member around a horizontal axis and a-vertical axis, the walls of said supplemental recesses holding said supplemental ball-member against substantial movement relative to the first ball-member in a direction parallel to the axis of said pivotmember, said supplementalball-member having a radial pin, said radial pin being sufficiently long so that its tip substantially abuts the wall of said first cup-shaped recess when said pivotmember is turned so that said outer end faces the wall of said first cup-shaped recess.

DAVID NEUSTADT. 

